This invention relates to an analog to pulse rate converter.
In the past, circuits have been provided for converting an analog input signal to an output signal wherein the output signal is a pulse train having a frequency which is related to the amplitude of the input analog signal. These prior art converters have typically been limited to a rather narrow dynamic range. Further, while such converters have been capable of monopolar operation, they have not been easily adapted for converting dual polarity analog input signals to a pulse train having a frequency which is proportional to the magnitude of the input signal.
It therefore is an object of this invention to provide an efficient and accurate analog to pulse rate converter having a wide dynamic range.
It is another object of this invention to provide an efficient, economical and accurate dual polarity analog to pulse rate converter.
Accordingly, this invention relates to an analog to pulse rate converter for converting an input analog signal to an output pulse train having a frequency which is proportional to the magnitude of the input signal. The converter utilizes C-MOS circuitry in order to conserve power and improve the accuracy of the circuit. The circuit includes an integrator for integrating the analog input signal wherein the integrator is operated substantially in its linear region. A threshold detector formed of C-MOS components detects when the output of the integrator reaches a predetermined threshold level. The output of the threshold detector is coupled to a JK flip-flop which provides an output pulse having a predetermined pulse width. The output of the JK flip-flop is coupled back to a reset switch which when closed resets the integrator to a reference level. The JK flip-flop is then reset and the reset switch is opened so that the integrator can then again integrate the analog input signal until the threshold level is again reached.